Tree Supports vs Normal: When to Use Each and Settings

Support structures are a necessary evil in FDM 3D printing. Overhangs beyond 45-50 degrees need something underneath them, or they droop and sag. Traditional supports are grid-like pillars that grow straight up from the build plate or the model surface. Tree supports are a smarter alternative — branching, organic structures that reach up and curve to support overhangs from a distance, using less material and leaving cleaner surfaces.

Understanding when to use tree supports versus normal (linear) supports, and how to configure them, can significantly improve your print quality and reduce post-processing time.

How Tree Supports Work

Tree supports grow from the build plate as a trunk, then branch out like a tree to reach overhang areas. Key characteristics:

• They grow around the model rather than straight up through it
• Branches only touch the model where support is needed — minimal contact area
• They use less material than normal supports because they share a common trunk
• They are easier to remove because the contact points are smaller
• They leave better surface finish on supported areas

Normal supports, by contrast, grow straight up from wherever the overhang is, creating a dense grid that uses more material and bonds more aggressively to the model surface.

When to Use Tree Supports

Tree supports excel in specific scenarios:

Best cases for tree supports:

• Organic shapes (figurines, busts, sculptures) where overhangs are scattered across the model
• Models with internal overhangs where normal supports would be impossible to remove
• Miniatures and detailed models where support contact marks must be minimal
• Models that touch the build plate at a few points with overhangs high up
• Any time you want easier post-processing

When normal supports are better:

• Large flat overhangs (like a shelf or ledge) — normal supports provide more uniform support
• Functional parts where dimensional accuracy on the overhang surface matters more than finish
• Very heavy overhangs that need the structural strength of dense grid supports
• Quick prints where slicing time matters — tree supports take longer to generate in the slicer

According to All3DP's support guide, tree supports reduce material usage by 30-50% compared to normal supports for typical models while providing comparable or better support quality.

Tree Support Settings in OrcaSlicer / PrusaSlicer

OrcaSlicer and PrusaSlicer share the same tree support implementation (inherited from BambuStudio).

Support Type: Tree
Support Threshold Angle: 45° (supports overhangs steeper than 45°)
Tree Support Branch Angle: 40° (max angle branches can lean)
Tree Support Branch Diameter: 2.0 mm
Tree Support Branch Distance: 1.0 mm (gap between support tip and model)
Tree Support Wall Count: 0-1 (0 for easier removal, 1 for stability)
Support Interface Layers: 2-3 (dense layers at the top of supports)
Support Interface Spacing: 0.2 mm
Support on Build Plate Only: Depends on model (see below)

Key settings explained:

Threshold Angle (45°): This determines what counts as an overhang. The default 45° means any surface angled more than 45° from vertical gets supported. Most printers handle 45° overhangs without support, so this default is appropriate. Increase to 50-55° if your printer handles overhangs well and you want fewer supports.

Branch Diameter: Thicker branches (3-4mm) are stronger but harder to remove. Thinner branches (1.5-2mm) break off easily but may fail on heavy overhangs. Start at 2mm.

Support Interface: These are the dense layers between the support tips and the model. They create a smoother supported surface. Use 2-3 layers with 0.2mm spacing for a good balance of surface quality and removability.

Tree Support Settings in Cura

Cura was the first major slicer to implement tree supports and has robust settings.

Support Structure: Tree
Support Overhang Angle: 45°
Tree Support Branch Angle: 40°
Tree Support Branch Diameter: 2.0 mm
Tree Support Branch Diameter Angle: 5°
Tree Support Collision Resolution: 0.15 mm
Support Z Distance: 0.2 mm (one layer gap)
Support Interface: Enabled
Support Interface Density: 50%

Cura-specific tips:

• Branch Diameter Angle controls how quickly branches thicken toward the base. Higher values create sturdier trunks.
• Collision Resolution affects how accurately the tree avoids the model. Lower values are more accurate but slower to slice.
• Cura's tree supports are generally faster to slice than OrcaSlicer's for complex models.

"Support on Build Plate Only" — When to Enable

This setting restricts supports to growing only from the build plate, not from the model surface.

Enable it when:

• Your model has overhangs only at the top that can be reached by tree branches growing from the base
• You want zero support marks on the model's vertical surfaces
• The model has enough base surface area for tree trunks

Disable it when:

• Overhangs exist in locations that tree branches from the build plate cannot reach
• The model has internal cavities that need support
• The overhang area is very large and needs support directly underneath

For most models, try "Build Plate Only" first. Tree supports are specifically designed to reach overhangs from the build plate — that is their primary advantage over normal supports.

Material-Specific Support Tips

PLA Supports

PLA tree supports break off cleanly. Use the standard settings above. For a printer with good cooling like the Bambu Lab P1S, PLA tree supports peel off with almost no surface marks.

PETG Supports

PETG tree supports are harder to remove because PETG bonds more aggressively between layers. Increase the Z distance to 0.3mm (1.5 layers) and reduce interface density to 40%.

ABS Supports

ABS tree supports remove similarly to PLA. Standard settings work, but consider increasing branch diameter to 2.5mm for stability in the warm chamber environment.

Soluble Supports (PVA, BVOH)

If you have a multi-material printer, use soluble support material for tree supports. The tree structure dissolves in water, leaving a perfect surface with zero post-processing. The Polymaker PolyDissolve S1 is a popular PVA option.

Support Interface: The Secret to Good Surfaces

The support interface is the layer(s) between the support structure and the model. Without it, the model surface in direct contact with tree branch tips looks rough with individual contact points visible.

With support interface enabled:

• 2-3 dense layers create a smooth platform at the top of each branch
• The supported surface is much smoother
• Removal is still easy because the interface is separated by the Z gap

Recommended interface settings:

Interface Layers: 3 (top and bottom)
Interface Pattern: Rectilinear or Grid
Interface Density: 60-80%
Interface Z Distance: 0.2mm (one layer height)

According to Prusa's support guide, support interface layers are the single most impactful setting for supported surface quality.

Painting Supports (Manual Support Placement)

Both OrcaSlicer and PrusaSlicer support "paint-on" supports where you manually mark areas that need (or must not have) supports.

When to use manual support painting:

• The automatic support generator adds supports where you do not want them
• You know from experience that certain areas do not need support despite the angle
• You want to minimize supports to the absolute minimum

How to use:

1. In the slicer, switch to the Support Paint tool
2. Green = enforce support here
3. Red = block support here
4. Paint directly on the model surface
5. Preview the supports to verify coverage

This gives you the efficiency of tree supports with precise control over where they appear.

Troubleshooting Tree Support Issues

Supports Fail Mid-Print (Detach or Fall Over)

• Increase branch diameter to 2.5-3mm
• Add more wall loops to the trunk (1-2)
• Reduce branch angle so supports grow more vertically
• Ensure good build plate adhesion with a brim on the support base

Supports Are Too Hard to Remove

• Increase Z distance (gap between support and model) from 0.2 to 0.3mm
• Reduce interface density from 80% to 50%
• Reduce the number of interface layers

Support Leaves Rough Surface on Model

• Enable support interface if not already
• Increase interface density for smoother surface
• Ensure Z gap is at least one full layer height
• Sand the supported area after removal — 200-grit sandpaper cleans it up quickly

Slicing Takes Forever with Tree Supports

• Increase collision resolution (0.2mm instead of 0.15mm)
• In OrcaSlicer, reduce the "Tree Support Detail" level
• Tree supports on very complex models can take minutes to generate. This is normal for organic shapes with many overhangs.

Tree vs Normal: Quick Decision Guide

| Scenario | Recommended Support | |---|---| | Figurine / miniature | Tree | | Flat shelf overhang | Normal | | Internal cavity | Normal (or tree with support on model) | | Organic sculpture | Tree | | Quick prototype | Normal (faster to slice) | | Minimal post-processing | Tree | | Multi-color with soluble support | Either (both dissolve) | | Large heavy overhang | Normal (more stable) |

Find Models to Practice Support Settings

Search 3DSearch for "overhang test" or "support test" to find models specifically designed for testing support configurations. Print these before committing to a complex model with extensive overhangs — it is much cheaper to dial in settings on a small test piece.

Final Thoughts

Tree supports are one of the best innovations in modern slicers. They use less material, leave cleaner surfaces, and are easier to remove than traditional supports. Use them as your default for organic and complex models, switch to normal supports for large flat overhangs, and use paint-on support tools for precise control. With the right settings, tree supports turn support removal from a dreaded chore into a satisfying peel.